(0, 200)

(200, 0)

(0, 300)

O(0, 0)

O = (0, 0)
A = (200, 0)
A' = Rotate(A, 90.0°, O)
α = Angle(A, O, A')
a = Ray(O, A)
B = (0, 200)
b = Ray(O, B)
C = Point(b)